Sign in
Please select an account to continue using cracku.in
↓ →
The number of real solutions of the equation $$(x^2 -15x + 55)^{x^2 - 5x + 6} = 1$$ is:
Correct Answer: 6
We need to find out the number of real solutions of the equation $$(x^2 -15x + 55)^{x^2 - 5x + 6} = 1$$
We can assume that $$x^2-15x+55$$ = $$P$$ and $$x^2-5x+6$$ = $$Q$$
$$P^Q=1$$
There are three possible cases
Case 1: $$P\ =\ 1$$ and $$Q\in\ R$$
$$x^2-15x+55$$ = 1
$$x^2-15x+54$$ = 0
$$\left(x-9\right)\left(x-6\right)=0$$
x = 9 and 6
Case 2: $$P\ \in\ R$$ and $$Q\ =0$$
$$x^2-5x+6$$ = 0
x = 2 and 3
Case 3: $$P\ =-1$$ and $$Q\ =$$ even positive power
$$x^2-15x+55$$ = -1
$$x^2-15x+56$$ = 0
x = 8 and 7
When x = 8 and 7 , Q = 30 and 20
Therefore, the number of possible values of x is 6. (9,6,2,3,8,7)
Create a FREE account and get: